[HOT] Helping Japan by tracing

Andy Gates andyg at ravenfamily.org
Tue Mar 15 11:25:58 GMT 2011


> the coastline in Japan is coming from the Japanese governement and
> tends to be pretty good. It is the reason why they are both
> natural=coastline and boundary=administrative.

If the tsunami has significantly _altered_ coastline, that'd be a reason
to change the natural tag.  I haven't seen any yet in the post-quake
imagery.

> MLIT is one of the Japanese ministries which has tons of open Data.
> Some of the data can be pretty old some can be pretty recent. I suspect
> you can alter them if you feel that the imagery represents the ground
> truth, but be aware that some of those forests are huge.

The forests look like they were drawn from low-res sources and
interpolated to smooth them out.  Certainly there are lots of cases where
they don't reflect the ground truth even approximately, which may be down
to the passage of time, and may also be a photogeographer or algorithm
getting confused between forest and farmland.

Knolls of raised land with a forested skirt are some of the coastal areas
which have weathered the tsunami well, so I'm amending the big import
forests.  Notability be damned, the groundtruth is different.

cheers,

   andygates





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